1. Field of the Invention
The present invention relates to the conditioning of liquefied petroleum fuels, and more specifically to a fuel-conditioning device for removing moisture, or other contaminants from the fuel.
2. Description of Related Art
Liquid petroleum fuels are often used for appliances such as furnaces, ovens, stoves, water heaters, and direct-fired absorption refrigerant systems. Examples of such manufactured fuels include propane, butane, propylene, butylenes, iso-butane, and various mixtures thereof.
As compared to natural gas, manufactured fuels are often a wet, contaminated fuel, due to the industry's transport, test, and storage methods. Propane, for example, is often transported in bulk rail, truck, and barge containers rather than piped. Water may be introduced into the propane through periodic hydrostatic burst strength testing of the transport/storage containers and/or steam cleaning of the containers following bulk transport of other contaminating materials, such as ammonia.
Since propane is hydroscopic and less dense than water, the water tends to collect at the bottom of the containers at the inlet to the container's off-load standpipe. Consequently, water is often the first material removed when off-loading bulk liquid propane. To minimize this problem, regional and local distributors of propane routinely add methanol to disperse the water more evenly throughout the propane. Unfortunately, the entrained moisture is then forwarded onto the final point of use where the liquid propane vaporizes just prior to combustion. Moisture at this point can contaminate valves, burners and other components associated with the appliance that burns the gas.
Once delivered to its general destination of use, propane is routinely stored outdoors in a pressurized tank above ground. Before the propane is conveyed to the heating appliance, a pressure regulator between the tank and the appliance reduces the propane's pressure to a level appropriate for the appliance. During the winter or when the outdoor temperature is relatively cold, moisture can precipitate at the pressure regulator, due the cold propane becoming even colder as its pressure is reduced. The precipitated moisture can interfere with the function of the pressure regulator and/or interfere with combustion at the appliance.
Various driers can be used to remove the moisture from fuel; however, the driers themselves can eventually become saturated with moisture. So, the driers may require periodic servicing to remove the moisture from the system entirely. Unfortunately, periodic servicing of a drier may require that the gas be temporarily shut off, which may interfere with the operation of the appliance.